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United States Patent | 5,515,683 |
Kessler | May 14, 1996 |
A thermoelectric heating and cooling chamber is characterized by a large adjustable temperature range. A layer arrangement of plate-shaped Peltier elements includes a first number of lower power Peltier elements that form a first, inner heating/cooling area and a second number of higher power Peltier elements that form an outer heating/cooling area. The two heating/cooling areas are separated by an overlapping intermediate plate of thermally-insulative material such as stress-free cast aluminum. To avoid overheating of the inner layer of the lower power Peltier elements during heating operation, either the cascade arrangement of the higher power Peltier elements is bypassed by a bypass diode polarized so that the electrically bypassed higher power Peltier elements remain currentless during heating operation, or a means limits current through the higher power Peltier elements as a function of a permissible temperature limit on the hot side of the lower power Peltier elements.
Inventors: | Kessler; Rolf (Merzhausen, DE) |
Assignee: | Litef GmbH (Freiburg im Breisgau, DE) |
Appl. No.: | 406891 |
Filed: | March 21, 1995 |
PCT Filed: | September 22, 1993 |
PCT NO: | PCT/EP93/02571 |
371 Date: | March 21, 1995 |
102(e) Date: | March 21, 1995 |
PCT PUB.NO.: | WO94/07094 |
PCT PUB. Date: | March 31, 1994 |
Sep 22, 1992[DE] | 42 31 702.9 |
Current U.S. Class: | 62/3.7; 62/3.3; 62/3.6; 62/324.1 |
Intern'l Class: | F25B 021/02 |
Field of Search: | 62/3.2,3.3,3.7,3.6,159,160,324.1,324.2 |
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